CO Interaction with Small Rhodium Clusters from Density Functional Theory:  Spectroscopic Properties and Bonding Analysis

Mineva, Tzonka; Russo, Nino; Freund, Hans‐Joachim

doi:10.1021/jp0116398

Cited by 31 publications

(31 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among these functionals, the results of BP86 are closest to the experimental data as reported in Table 1. It should be note that the BP86 functional has been applied successfully to several systems, including Si n M [39] (n = 4-11) with M = Cu, V and especially for rhodium system as denoted in the literature [40][41][42]. In consideration of above calculated results and these applications, we adopt the BP86 exchange-correlation functional in the present study.…”

Section: Methodsmentioning

confidence: 99%

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Hang

Hung

Thiem

et al. 2015

Computational and Theoretical Chemistry

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Hang

Hung

Thiem

et al. 2015

Computational and Theoretical Chemistry

View full text Add to dashboard Cite

“…The peak shi indicates that hydrogen insertion into the Rh carbonyl bond occurs under formation of (Rh(H)CO and/or Rh(H 2 )CO). 74,75 The corresponding Rh-H stretching vibrations are expected in the range between 2100 and 1900 cm À1 and may contribute to the broadening of the signal near 2000 cm À1 . 54 Hydrogen insertion into CO bonded to metallic Rh causes an increase in p-donation from the metal towards the antibonding p-orbital of the p-acceptor ligand (i.e., CO) and thus a red shi of the CO stretch occurs.…”

mentioning

confidence: 99%

Insights into structure and dynamics of (Mn,Fe)O_x-promoted Rh nanoparticles

et al. 2018

View full text Add to dashboard Cite

The mutual interaction between Rh nanoparticles and manganese/iron oxide promoters in silica-supported Rh catalysts for the hydrogenation of CO to higher alcohols was analyzed by applying a combination of integral techniques including temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and Fourier transform infrared (FTIR) spectroscopy with local analysis by using high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) in combination with energy dispersive X-ray spectroscopy (EDX). The promoted catalysts show reduced CO adsorption capacity as evidenced through FTIR spectroscopy, which is attributed to a perforated core-shell structure of the Rh nano-particles in accordance with the microstructural analysis from electron microscopy. Iron and manganese occur in low formal oxidation states between 2+ and zero in the reduced catalysts as shown by using TPR and XAS. Infrared spectroscopy measured in diffuse reflectance at reaction temperature and pressure indicates that partial coverage of the Rh particles is maintained at reaction temperature under operation and that the remaining accessible metal adsorption sites might be catalytically less relevant because the hydrogenation of adsorbed carbonyl species at 523 K and 30 bar hydrogen essentially failed. It is concluded that Rh 0 is poisoned due to the adsorption of CO under the reaction conditions of CO hydrogenation. The active sites

show abstract

“…8 A scaling factor of ∼0.95 would be typical for DFT calculations, but, since ν(CO) is significantly decreasing from Rh 7 CO to Rh 6 CO, a further decrease might occur when going to the smaller clusters.…”

mentioning

confidence: 99%

Vibrational Spectroscopy of CO in Gas-Phase Rhodium Cluster−CO Complexes

et al. 2003

View full text Add to dashboard Cite

Interest in the chemistry of transition metal atoms and small clusters dispersed on insulating supports goes back many years. 1 Driven by the catalytic activity of metals such as rhodium dispersed on amorphous metal oxides supports, this interest is now strengthened due to the possibility of harnessing size-specific properties in heterogeneous catalysts. New insights into the chemical properties of small deposited metal clusters have been gained from the sizeselective preparation of cluster deposits on ordered substrates as well as from characterization techniques that have a high spatial resolution such as the scanning probe microscopies. 2,3 One of the techniques that is most widely used to characterize supported metal particles is infrared (IR) spectroscopy of adsorbed carbon monoxide, CO. The stretching frequency of CO, ν(CO), is highly sensitive to structure and electron density at the binding site. The interpretation of the vibrational spectra of CO chemisorbed on supported metal systems relies on the comparison with ν(CO) values in stable metal carbonyl compounds, on single crystal surfaces, and with atom-CO complexes in rare gas matrixes. Until now, there is no information for isolated unsaturated metal cluster carbonyls, as conventional IR spectroscopic techniques are difficult to apply for those species.Here, we report on the vibrational spectroscopy of gas-phase rhodium cluster complexes with CO, Rh n CO (n ) 6-20), one of the most widely studied supported transition metal systems. Spectra in the region of ν(CO) are obtained using IR multiphoton depletion (IRMPD) spectroscopy. These gas-phase studies provide fundamental insight into metal-ligand interactions and additionally allow one to distinguish between intrinsic properties and support effects in supported clusters. The experiments take advantage of the tunable, IR radiation from the free electron laser for infrared experiments (FELIX) 4 which is ideal for IRMPD spectroscopy of cluster-ligand complexes. 5 Briefly, the IR induced fragmentation yields of the clusters in a molecular beam are monitored under FELIX irradiation as a function of IR frequency using mass spectrometry. Details are available as Supporting Information.In Figure 1 parts of mass spectra are shown around the mass of Rh 6 obtained under FELIX irradiation at two different IR frequencies. The peak due to Rh 6 CO, visible with 2026 cm -1 radiation is completely depleted with 1950 cm -1 radiation. The inset in Figure 1 shows the IRMPD spectrum for Rh 6 CO. Clearly, a resonance can be seen that can be straightforwardly attributed to the ν(CO) stretching vibration of Rh 6 CO. Similar depletion spectra have been obtained for Rh n CO with n ) 6-20. Spectra for n ) 6-15 are shown in Figure 2, and the peak frequencies are summarized in Table 1. The frequency scale is calibrated on ethylene absorptions measured in a photoacoustic cell, resulting in an absolute frequency accuracy better than (2 cm -1 . Rh 6 is the smallest cluster for which we can observe CO complexes, as the smaller Rh n C...

show abstract

CO Interaction with Small Rhodium Clusters from Density Functional Theory: Spectroscopic Properties and Bonding Analysis

Cited by 31 publications

References 49 publications

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Insights into structure and dynamics of (Mn,Fe)O_x-promoted Rh nanoparticles

Vibrational Spectroscopy of CO in Gas-Phase Rhodium Cluster−CO Complexes

Contact Info

Product

Resources

About

CO Interaction with Small Rhodium Clusters from Density Functional Theory: Spectroscopic Properties and Bonding Analysis

Cited by 31 publications

References 49 publications

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Electronic structure and thermochemical properties of neutral and anionic rhodium clusters Rhn, n=2–13. Evolution of structures and stabilities of binary clusters RhmM (M=Fe, Co, Ni; m=1–6)

Insights into structure and dynamics of (Mn,Fe)Ox-promoted Rh nanoparticles

Vibrational Spectroscopy of CO in Gas-Phase Rhodium Cluster−CO Complexes

Contact Info

Product

Resources

About

Insights into structure and dynamics of (Mn,Fe)O_x-promoted Rh nanoparticles